It is important for the development of pharmaceutical products to improve dissolution property of poorly soluble drugs. As a technique for improving dissolution property of poorly soluble drugs, pulverization of a poorly soluble drug by a precipitation method, wet grinding and the like, and formation of a salt or cocrystal of a poorly soluble drug are known (patent documents 1-4 and non-patent documents 1-4). As used herein, the “cocrystal” generally means a crystal in which multicomponents constituting the cocrystal are linked by a bond or an interaction other than an ionic bond.